Mr Sargeant said: "The language used by Mr Cottle in his rant is racist, abusive and profane. This man is paid for by the taxpayer, those very people he seems to bear so much hatred towards. He is supposed to encourage businesses to operate bilingually, an important job and crucial to the Labour Assembly's goal of encouraging a bilingual Wales.

"It is impossible to see how he can continue to do this after such a series of tirades."

The AM claimed messages from the same e-mail address also appeared on the Welsh lobby group Cymuned's web-site supporting a "No Colonisation" sticker campaign.

Mr Sargeant said in a letter released to the Daily Post: "From what I know of Mr Cottle's job, he is supposed to encourage local businesses to operate bilingually.

"This is an important job, but I fear that behaviour such as this from one of your senior members of staff will have a counterproductive effect on the growth of the Welsh language in Flintshire.

"I find these comments racist, abusive and ignorant."

Menter Iaith Flintshire chairman Dewi Jones said yesterday: "I haven't received Mr Sargeant's letter and so don't feel able to comment on it.

"I've expressed to Aled my disappointment at his choice of language." "However, the e-mail was sent from his home computer and we cannot be responsible for action staff take outside of work hours."

Mr Cottle denied involvement in the e-mail when first contacted by the Daily Post and later declined to comment.